Electric plug



April 14, 1936. N. cHlRr-:LsTElN ELECTRIC PLUG Filed sept. 14, 1955Patented Apr. 14,` 1936 UNITED STATES PATENT ioFFlcE 1 Claim.

My invention relates to electric socket plugs. The object of myinvention is to provide an improved attachment plug embodying means forholding the contact members of the male and female portions of the plugin rm contact over a lconsiderable surface'to effect perfecttransmission of an electric current therethru.

A further object is to provide a male portion having blades or legs ofless thickness than those of the standard type now in general use, toren-- der them more resilient so that they will bend without breakingeither the-legs or the plastic material base to which they are attached,and also to permit them to bend easily in opposite directions from themedian line thru the recesses of the female member, to'effect contactAover a considerable surface with the socket conductors, regardless ofwhich side of the recesses they may be located in. l

A further object is to provide a plug in which the contact members willbe held together under constant spring pressure over a considerable areato eiect a frictional engagement therebetween regardless of which sideofthe recesses the contacts may be located in the female member.

Referring to the drawing which forms-a part of this specification;

Fig. 1 is a vertical sectional view of the plug, in which the male andfemale portions are united in current conduction relation.

Fig. 2 is a view of the inner end of the male portion looking in thedirection of the arrows 2,-2 of Fig. 1.

y Fig. 3 is an illustrative view showing the leg,

as it appears when in contact with the conducting strip located on theinner side of the recess of the femalemember.

Fig. 4 is a view, partly in section, of the male portion of the plug.

Fig. 5 is a perspective view of a leg formed as shown in Fig. 4.

My invention is embodied in the male portion of the plug.

III indicates the female or socket portion of the plug which is of thestandard type, some of which have the conduction terminals located onthe inner walls of the recess and some of which yhave them locatedadjacent the outer walls of the recesses.

In Fig. 1 the terminals are shown located adjacent the outer walls ofthe recesses Il, and i2 .inner sides of the indicates the face of thebody portion of the male member.

Fig. 3l shows a socket portion of a plug in which the contact members I2are located adjacent the u indicates'the body-portion of the malemember, which may be made of hard plastic or soft rubber in the usualmanner.

II indicates the male contact members, hereinafter referred to as thelegs or as the blades. Thel legs are fastened to the body portion byscrews I6 which extend thru theplate portions Il in thefusual way, ortheymay be attached in any other satisfactory manner.I

The legs normally extend straight from the body portion parallel witheach other, and enter the socket recesses midway between the wallsthereof, and the branch portions I9 extend from the free ends of thestems to the face of the body portion.

When the legs are used in a socket having its terminals locatedvadjacent the inner walls, as shown in Figure 3, the stem portions bendor flex the greater distance, whereas when used as shown in Figure 1,the branch portion is bent more than the stem portion.

It will be noted that' the branch portion is provided by bending thestem at 2| into the position and shape shown, and some metal is punchedout to provide the slots 22. These slots weaken the stem and branchportions at these points, thus making them more flexible, and causes asharper bending of the branch at 23, providing a shoulder to be formedautomatically when the leg is forced into the socket. c

The drawing illustrates 4the plug on a scale twice the size of theactual construction.

The metal stem and its branch are of equal thickness, aboutone-thirty-second of an inch, and this reduction in thickness relativeto onesixteenth of an inch as now generally used in standard plugs ofthis type, provides a plugvhaving very flexible and resilient legs whichaccommodate themselves to socket constructions in which the walls of therecesses and the terminals are badly worn, making good contact with saidterminals regardless of which side of the recesses they may be locatedadjacent to.

. It will be notedthat the branch portions are free ended and projectfrom near the entering ends of the blades and extend toward the bodyportion a distance at least equal to the contacting length of the bladesso that the free ends will not operate to lock or prevent uncoupling theplug by simple withdrawal. When coupled, each blade and its respectivebranch portion is wedged toward each other against the receptaclecontacts, thereby obtaining spring pressed contacty and good mechanicalconnection.

A considerable number of these plugs have been made and usedsuccessfully with both types of socket members, and the body portions ofthey tact blades extending therefrom, said blades b'e-v ing formed ofresilient conducting metal and spaced apart a distance corresponding tothe separation between the socket openings of a standard receptacle,said blades each having a free ended branch portion integralE therewithand projecting from near the entering end thereof toward said bodyportion a distance at least equal to the contacting length of the bladeand said branch portion comprising an extension of said blade foldedback in contact therewith at the entering end and diverging awaytherefrom; the construction being such that each blade and itsrespective branch portion will be wedged toward each other against thereceptacle contacts in the act of coupling the plug,4 thereby obtainingspring pressed contact and good mechanical connection.

NATHAN CHIRELSTEIN. v

